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In the EU-funded Climate for Culture (CfC) project, an interdisciplinary research team of 27 partners investigated the impact of climate change on Europe’s cultural heritage buildings and their interior collections. Thereby regional climate models and building simulation tools were coupled to assess the outdoor and indoor implications. Two different climatic scenarios, A1B and RCP 4.5, from the 4th and 5th IPCC-report were used as baseline for the projection of future outdoor climate data. The regional climate model REMO was applied for high-resolution simulations of outdoor climate over Europe and the Mediterranean for both climatic scenarios. These calculated climate indices were used as input for hygrothermal building simulation tools allowing a prediction of future indoor climate and its risk potential to interior objects.

To investigate the long-term impact of climate change on a variety of historic buildings the CfC project used the so-called “Generic Sacred Buildings”: 16 fictitious but representative building models of unconditioned buildings like churches or monasteries, which are based on measurements of existing buildings collected during the CfC project. These Generic Sacred Buildings were placed on 474 locations all over Europe and the Mediterranean and building simulation tools were applied to simulate indoor climate for three time-windows: 1960 – 1990, 2020 – 2050 and 2070 – 2100. Afterwards, each indoor climate, in particular temperature and relative humidity, was evaluated by using a newly developed automated method which assesses nearly 200 parameters, like for example temperature, relative humidity, deterioration rates or various damage risks. All results of this assessment process were collected and visualised as pan-European maps. Also the differences between the three time-windows were calculated for every parameter allowing the identification of changes from past to future periods.

Because of the sheer amount of available data, more than 52.000 maps were produced, the here presented evaluation of future indoor climate projections focuses on some selected parameters. A common insight from the maps is that mean indoor temperature will increase all over Europe for all investigated building types. As a result of the temperature development, frosting time inside the buildings decreases, mostly in Northern and Eastern Europe. An often inquired damage process is mould growth on collection objects. The maps hint, that mainly in Northern and Eastern Europe possible risks of mould growth will increase in future periods. Furthermore insect growth conditions inside the buildings were evaluated by calculating degree-days. Favourable growth conditions can be found around the Mediterranean and with increasing temperature in future time-windows these will also increase in Northern and mostly in the middle parts of Europe. The assessments also include risks for mechanical damages of wooden objects like panel paintings, statues or furniture. These damage risks were evaluated by analysing long- and short-term changes in relative humidity and show mostly a stable risk classification during the time-windows. Also chemical degradation processes were evaluated by using Lifetime-Multipliers. They indicate increasing damage risks mostly around the Mediterranean.

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The urban fabric is affected by both climate and air pollution, but the magnitude of their impact varies over time. The effects of air pollution on the degradation and soiling of materials were particularly noticeable during periods of rapid urbanization, while the late 20th century has seen a reduction as a result of the decline in the aggressive pollutants such as sulfure dioxide. Soiling is more complex as there have been changes in the nature of the deposited particles over time, but as with the gaseous pollutants there have been improvements that accompanied more stringent regulations designed to improve air quality. Over the centuries there has been an increase and subsequent decrease in the rate of damage to building materials which can be interpreted in terms of the environmental Kuznets curve. The decline in the aggressiveness of pollutants in Paris makes it likely that climate driven processes will on balance play a bigger role in the future. Historically frost damage was important, but it is hardy likely to be relevant in a warmer future. This presentation attempts to estimate the rates of recession and soiling of calcareous stone and damage to glass and stained glass in Paris over many hundreds of years and understand how these processes will change through to the end of the 21st century. The long term variation of air pollution is assessed on the basis of past observations and estimated for the future from likely regulatory trends. Meteorological input derives from historical data and some non-instrumental weather records, while future climate is adapted from the Hadley Centre and Météo-France models under a2, RCP2.6 and 8.5 scenarios for the 21rst century. Converting this environmental input to long term change in damage has used dose-response functions from a range of sources to estimate the magnitude of the changes and where possible compare these with historical observations of the state of buildings made by architects and other observers.

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The preservation of historical buildings and outdoor cultural heritage is a necessity to hand down to the posterity works of art, as well as to guaranty an economic resource. The main causes of degradation of stones, one of the most important porous materials of these artifacts, are related to the chemical-physical processes that influence the ingress and diffusion of water (liquid or vapor) into the pore space. It is well known that water dissolves CO2 and pollutants from the atmosphere, causing acidic corrosion of the stone or the binder, and it is responsible of internal mechanical stresses due to freezing-thawing cycles or salt crystallization.

For the treatments, usually hydrophobic compounds (typically synthetic polymers) are applied, with performance (efficiency and durability) that depends on the compounds used, the treatment procedure and the chemical-mineralogical nature of the substrate. Many are the characteristics of the products to guaranty good performance: high stability (chemical, thermal and to photo-oxidation), high adhesion to the mineral substrate (interaction but not reaction with stone), low surface tension and suitable molecular dimensions which allow a uniform distribution, good penetration into the porous structure, and low propensity to pore blockage. Very important is the solubility of the product in solvent safe for man and environment. Perfluoropolyethers, applied on some historical buildings since the 1980s, have high stability, water repellency and low surface tension, but the protective treatment showed a low durability. Perfluoropolyethers containing polar groups able to give better interaction with stone, typically ester and amidic groups, were developed. Unfortunately, these compounds are soluble only in CFC and in supercritical CO2, therefore their use as protective agents for historical stone artifacts was abandoned since the 1995.

This work was focused on the preparation of a new protective agent with low average molecular weight containing short pendant perfluoropolyether segments linked to an oligosuccinamide chain in order to achieve: (i) high hydrophobic effect and photo-stability, (ii) good adhesion to the rock through the polar amidic groups, (iii) excellent distribution on the pore walls surface without their blockage, (iv) solubility in environmental friendly solvents.

Hydrophobic penetration and distribution properties of the compound applied on a biocalcarenite (Lecce stone), have been investigated by Nuclear Magnetic Resonance (NMR) Imaging, Profiling and Diffusometry of 1H nuclei, and compared with a perfluorinated commercial product. These NMR techniques has been proved to be a valid non-destructive and non-invasive technique for monitoring the conservation state and water absorption in materials and objects of interest to cultural heritage, as well as for evaluating the efficiency and distribution of protective or consolidation treatments.

The results obtained by Imaging were compared with those obtained by single-sided NMR apparatus. This last instrument, that allows for in situ non-destructive analyses, was equipped with a lift for automatic shift of the NMR sensor and allowed us to obtain high spatial resolution profiles of the NMR signal inside the samples. Two-dimensional correlations maps of the two parameters self-diffusion coefficient and NMR relaxation time gave further information on the performance of the treatments. The results demonstrate that the partially fluorinated oligoamide satisfies the main properties required to a protective agent (no color changes of the treated surface, high residual permeability and high photo-oxidation stability), and improves the water repellency of treated stone surfaces in respect to a fluoroelastomer,

Urban planning and design to mitigate climate change impact: the role of heritage conservation in a dense urban city

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Climate change and global warming has made urban heat island effects become more severe in cities facing rapid urbanization. The urban heat island phenomenon is even more severe in urban cities with the tall and massive high-rise building morphology. In contrast, built heritage sites consist usually of low rise buildings located in city centres. The conservation and adaptive reuse of historic buildings can provide potential breathing space among the high rise blocks to generate air paths and minimize the heat island effect. Thus, the careful planning and design of heritage sites can enhance human thermal comfort and mitigate the adverse impact of climate change in the dense urban cities, whilst preserving historic pride and cultural spot.

Climate change also alters the way that people live, work, worship or socialize in public space. What role can built heritage play in minimizing the adverse impacts of climate change on the microclimate of the urban environment? Conservation and Planning considerations should emphasize more on clusters of heritage sites in urban districts which can provide much greater impact on the overall urban environment than a single building.

This paper explores the relationship between climate change mitigation and built heritage conservation in a dense urban city.

It is proposed that a robust database of spatial maps will be constructed, of an urban districts in Hong Kong with the aid of GIS. The study maps will display the urban fabric including the locations of heritage sites, building height and mass, building footprint, land use, open space, and topography. Micro-climate environmental maps which include temperature, and wind velocity will also be compiled. Field measurements of the meteorological parameters at the selected studied heritage sites will provide supplementary data for the spatial maps.

Despite the robust maps and measurement are important, the ways in which conservation of heritage buildings can influence the social experience of adapting to climate change would be worth for investigation. The impact of climate change should not be limited to physical and environmental impacts, in fact, the socio-economic changes due to climate change will have also have a great impact on the conservation of cultural heritage. On one hand, climate change alters the ways that people, in relation to the environment they live, work, worship and socialize in buildings, sites and landscapes with heritage values. For example climate change modifies the social interaction patterns in public spaces. On the other hand, heritage can also affect the social experience of climate change. Heritage conservation can have a positive effect on the lives of people in a changing climate and how they perceive climate change. For example, a green common space in a heritage site can provide the community with a pleasant breathing space in the middle of high rise buildings.

Thus, it is of paramount importance to examine the extent to which the adaptive reuse of heritage buildings can also incorporate design considerations which mitigate the physical and social effects of climate change. This proposed research will help towards responsive and innovative solutions to the UHI effects and climate change with the conservation and reuse of heritage buildings. A better understanding of the links between built heritage, urban morphology and the surrounding microclimate is essential to create successful climate change mitigation strategies for dense cities.

The study will provide useful reference data for urban planners and urban designers helping them to incorporate environmental and social considerations on the conservation of heritage buildings, and most importantly, help to ensure the better use of heritage sites to mitigate climate change adverse impacts in dense urban cities.

Towards a Framwork for Evaluating Existing International Best Practices on Climate Change and Heritage

A. Potts (International Council on Monuments and Sites (ICOMOS), Washington, DC, United States of America)

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Towards a Framwork for Evaluating Existing International Best Practices on Climate Change and Heritage

A. Potts (1) (1) International Council on Monuments and Sites (ICOMOS), United States National Committee, Washington, DC, United States of America

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This presentation examines the response of the heritage sector to climate change with an emphasis on the key themes and theoretical frameworks that have been adopted by major organizations to date. It finds that a formal concern for the impact of climate change on heritage sites is increasingly being complemented by a broader concern for the impacts on social sustainability from the degradation of intangible heritage and “a sense of place” attendant to climate change. Attention is also increasingly being paid to the ways in which cultural heritage is a solution to climate change, for example offering lessons in past human successes and failures in adapting to environmental changes, and providing insight into the origins of the modern climatic situation.

It has now been almost a full decade since the issue of the impacts of climate change on natural and cultural heritage properties was formally brought to the attention of the World Heritage Committee. This resulted in an expert meeting in March, 2006 at the UNESCO headquarters in Paris which issued a joint report on “Predicting and Managing the Effects of climate change on World Heritage” as well as a “Strategy to Assist States Parties to the Convention to Implement Appropriate Management Responses.” The World Heritage Committee endorsed these two documents at its 30th session (Vilnius, 2006) and requested all States Parties to implement the strategy so as to protect the outstanding universal values, integrity and authenticity of the World Heritage properties from the adverse impacts of climate change. In 2007 climate change and heritage experts, including ICOMOS, issued a Policy Document on the Impacts of Climate Change on World Heritage Properties which among other things identified future research needs. Broadly speaking these documents provide guidance on (1) Monitoring and reporting; (2) Mitigation; (3) “Corrective actions” including management, adaptation, and risk management and (4) Collaboration, cooperation, and sharing best practices and knowledge.

As the world approaches the 10th anniversary of these reports, this presentation would examine the climate change strategies from major cultural heritage organizations around the world, using the 2006 and 2007 guidance documents as touchstones. Two examples of these heritage responses are those of the United States National Park Service (NPS) and the International Trust Organization (INTO).

INTO represents national heritage trust organizations in over 40 countries and has been represented at 4 of the last 6 COPs. INTO views climate change through the lens of the Victoria Declaration on the Implications for Cultural Sustainability of Climate Change which was adopted by INTO at its 14th International Conference of National Trusts held in 2011. The Victoria Declaration focuses on the capacity of climate change to undermine the integrity of the world’s cultures, and the resulting social dislocation and social instability likely to follow, framing these issues in terms of intergenerational equity.

The NPS is the lead US federal agency for the management of cultural heritage. In 2014, it signed a policy memo Climate Change and the Stewardship of Cultural Resources, which set out a leadership role that looks at both the impacts of climate change on heritage and the capacity to learn from these over time, and applies those to the four pillars of climate change response that NPS established in its 2010 Climate Change Response Strategy: science, adaptation, mitigation, and communication. While focusing on impacts, the Policy includes the science of learning from cultural heritage about climate and environmental change, for example, learning about human adaptation to climatic variability through time from cultural heritage and learning from heritage to reacquaint ourselves with energy-saving practices and methods that have become less used.

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Recently hygrothermal building simulation has been applied for the projection of damage risks from future indoor climate in historic buildings. This has been done using generic weather data obtained from dynamic downscaling of regional models with different global climate change scenarios (A1B and RCP4.5). The objective of this paper is the development and definition of new concepts to assess the accuracy of hygrothermal simulation models for indoor climate of historic buildings in the contexts of climate change and preventive conservation. Preventive conservation is aimed at the permanent conservation of works of art and objects of cultural value by improving ambient conditions and by reducing or minimizing relevant risks. The quality of simulations is of significant importance especially when assessing climatic risks in historic buildings with precious interieur and works of art, since misjudgements of planned measures can result in irreversible damages. Moreover, hygrothermal simulations offer new opportunities in calculating the effect of different measures to improve indoor climate. But also for the assessment of future risk it is important to know how reliable a simulation model is for the present. Therefore, it is important to develop criteria to assess the results of simulation with regard to preventive conservation, and to verify them by means of case studies. The indoor climate of the small village church St. Margaretha in Bavaria is characterized in detail by means of measured data and reproduced by means of simulation models. For this case study a new approach was developed using multiple criteria in the form of different damage functions for accuracy assessment. This assessment is only one important element in the chain of uncertainties that applies when using projected future climate data from global climate change projections. Therefore also the measured long-term outdoor climate from a weather station nearby has also been compared to the generic weather data for the recent past (1960-1990) for different climate change scenarios.

Panel discussion:

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Panel discussion:

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The balance of air pollution and climate as drivers of damage to heritage

P. Brimblecombe, (City University of Hong Kong, Kowloon, Hong Kong)

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The balance of air pollution and climate as drivers of damage to heritage

P. Brimblecombe, (1) (1) City University of Hong Kong, School of energy and environment, Kowloon, Hong Kong

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It has been well known from classical times that weather and smoke cumulatively damage buildings. The shifting climates of the past had an impact and historic exposure to aggressive air pollutants, especially those from coal which caused not only blackening, but led to surface recession and crust formation that resulted from high sulfur dioxide concentrations. The situation has changed as air pollution is more effectively regulated. Our understanding of the impact of climate on heritage assets requires the development of material or heritage climatologies that recognise the role of the combination of meteorological factors, cycles of climate and the long accumulation of damage. Although controversy surrounds long-term climate predictions, there seems little doubt that the world will become warmer and rainfall patterns will change, even if we cannot be sure of the magnitude. The changes are often quite small, just a few degrees change in temperature or percentage changes in rainfall or relative humidity. This means amplification is often necessary for the effects to be significant. Phase changes (freezing or salt crystallisation) can be important amplifiers, while biological effects (changing insect numbers or rapid fungal growth) can also enhance the outcomes from small temperature changes. The impact of changed rainfall can be increased by a larger number of wet days or longer times of wetness. The frequency of extreme events may also alter the rate of material damage. Air pollutants will doubtless be more regulated in the future, but new problems may arise through the presence of ozone and diesel particles in the air and novel pollutants might also have an impact.

Socio-cultural implications of Climate Change for Cultural Heritage

M. Cassar (University College London, London, United Kingdom)

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Socio-cultural implications of Climate Change for Cultural Heritage

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When considering the interaction between cultural heritage and climate change, the most media-visible effort on climate change is undoubtedly scientific research. Yet society requires science to have wider context and meaning. It needs to be relevant. Therefore the socio-cultural impact of climate change must be part of any discourse on the implications of climate change for cultural heritage.

Not only would this inform our understanding and influence our response to climate change impacts, it can also make our response more resilient and sustainable. There are inherent cultural and social dimensions to climate change. Artists and sculptors, writers and poets, performances and exhibitions engage the public with climate change in ways that are necessary and important. They provide critical pathways for adaptation. The arts and humanities, social sciences and economic disciplines provide different lenses through which to develop new responses to life-changing events. By developing a range of perspectives, we improve our chances of co-creating sustainable survival strategies.

Cultural heritage research until recently, has been largely concerned with the impact on ancient and historic materials and assemblies such as those caused by increasing sea levels and floods, changes in the moisture contents of the air and in the conditions of soil (especially for archaeological sites) and migration of pests. Yet cultural heritage is more than stones, bricks and mortars.

In addition to these impacts, climate change can severely affect the sustainable conservation of cultural heritage places by altering the traditional way of life of communities. The relationship of communities to their landscape, their work and social habits, can be affected by the rapid deterioration of physical assets and loss of authenticity[i].

In 2008, World Monuments Watch and the World Monuments Fund provided dramatic evidence of these consequences when it listed a number of places at high risk of loss due to the effects of climate change. These included:

Leh Old Town, India (from changing weather patterns in the Himalaya bringing more rain in the summer thus creating problems for the flat mud roofs designed for the originally dry climate);

Kilwa Historic Sites, Tanzania(from serious rapid deterioration of the archaeological and monumental heritage due to erosion and vegetation caused by rainwater wash accentuating the risks of collapse of the remaining structures on the edge of the cliff); and

If scientific research is to understand deeply the cause and effect of change on cultural materials, and if it is to develop sustainable adaptation strategies, the values associated with these places need to be integral to the solution. This contribution will focus primarily on the language that is used to highlight the significance of these endangered sites in order to evaluate the extent to which the socio-cultural impacts of climate change are integrated into scientific studies of cultural heritage.

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[i] UNESCO World Heritage Centre (2006) World Heritage Paper No. 22. page 10. Available at: http://whc.unesco.org/en/climatechange/ and published in English and French.

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Coastal heritage is comprised of many different types of artefacts. Some of them are located along the coast but have no direct relation with the sea (such as tombs, stones circles). Others (for example harbours, fisheries, dykes, shell middens…) do present a deep relation with the sea level, the wave directions, the local winds and possibly with sediment movements. The first group of heritage site may, today, be concerned by relative sea level rise and/or coastal retreat and beg for a protection. Though these archaeological objects may be moved inland and still keep most of their scientific value and cultural interest. In this case their land ward shift and protection is not vey different from their possible inclusion into a museum collection.

The other set of heritage sites is totally different. Most of their scientific value depends on their precise relation with the “natural” environment at the moment of their building. As objects they can be deconstructed and stored in a museum but as a site they cannot be understood outside of the very precise geomorphological setting where they were built. In these two cases the epistemological issues are clearly different. Though a large part of the scientific value is located inside of the object itself (it is a real property of the object, as realists philosophers have often explained it) some other dimension of the scientific knowledge is not in the object but in the relation it has with the local passed environment, and especially with the local ancient morphodynamic condition. Therefore what should be protected (or reconstructed) should not only be the object but the natural ancient environnement (the local site when sea level was different) and the ancient events which may have taken place such as storms or human induced soil erosion. The context of the object is as important as the object itself. This rises new questions about heritage and cultural approaches of heritage conservation. How can climatic events be understood as heritage ? How can ancient human induced erosion processes may be included into the wide and general notion of heritage? Our scientific knowledge about ancient processes is limited and new dating techniques regularly appear and help to produce new information. So there is an always wider range of objects which can be dated : with Pb 210 muds may be dated even when they do not contain organics. The question of how large is the accommodation space around the artefact is totally opened: how far from the object may the environnement provide relevant information? How far should the protected area be extended? Is this protected space compatible with other activities on the coast?

This speech present some pre roman examples in Brittany and some post cold war examples in Taiwan.

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Not only historical buildings and outdoor monuments are exposed to climate changes and related risks. The exchanges of air, heat and moisture through the building envelopes will affect the indoor climate too, with potential risks to collections, paintings, furniture etc. The potential impact of mechanical, chemical and biological agents will depend on the outdoor climate change, the building structure and the material type. In order to know the expected changes and assess risk factors, the EU funded "Climate for Culture" Project has investigated the problem and produced thematic maps over Europe, using the REMO regional climate model at 10 km ´10 km space resolution. Two moderate IPCC emission scenarios have been considered: A1B and RCP 4.5. The former to make comparisons with previous studies easier; the latter as updated reference. The situation has been calculated for two future time windows, i.e.: 2021-2050 near future and 2071-2100 far future. Changes have been highlighted calculating and mapping the difference between each future map and the related situation in the 1961-1990 past reference period.

The first step has been to calculate the outdoor climate (e.g. precipitation, dryness, temperature, humidity, time of wetness, repeated freezing thawing, salt crystallization cycles), then the indoor climate and finally the potential damage and risk factors. To this aim, it has been necessary to assess the impact of climate change through an improvement of the prediction models; then to develop a methodology to assess the climate-induced risks on materials and building envelopes. The study has been based on some 120 case studies plus 16 classes of generic building types, each class being characterized by a different building volume (small/large), structure (heavy/light weight), moisture buffering performance (low/high) and window area (small/large). A number of key materials (i.e. stone and masonry, metals, wood and veneers, painted wood, paper, silk and colour photographs) have been considered, either because they are commonly used in this field, or for the potential risk that may derive under certain unfavourable circumstances. The relevance of deterioration mechanisms and the risk factors have been calculated using specific damage functions, either known in literature or tested in laboratory within this Project. Damage functions and/or thresholds link the changes of the climate variables to a specific risk of damage. The level of risk has been defined according to the number of events that have exceeded some specific thresholds, or the time elapsed above them. A traffic light code (i.e. green colour: safe; orange colour: attention; red colour: risk) has been used to express the risk levels. At the end, a total of 55,650 high-resolution thematic maps over Europe have been produced.

The uncertainties related to the project outcomes include the uncertainty band in risk maps, forcing conditions and the used climate model, significance of the climate change pattern, building simulation, damage functions. The above uncertainties have been analysed to assess the confidence limits of the future scenarios that should be considered in view of any decision support/making system. Although the study has been focused on cultural heritage conservation, some outcomes might be useful for other social application fields, e.g. temperature changes and increased number of tropical days may be related to health, cultural tourism and energy consumption; mould growth and pest infestation to sick buildings. The recovery of early instrumental observations and various proxies has also been considered to produce long-term urban outdoor and indoor historic climate series (e.g. 1500-today), or to reconstruct the sea level in Venice (1200-today). This has been useful to improve understanding and to refine future simulations.

The analysis of the results shows that climate change may have negative, neutral or positive effects (e.g. faster or slower deterioration rates, more or less need for heating, cooling or humidifying) depending on specific problems, aims, solutions, and building use. These results offer a timely information to prepare adaptation and mitigation strategies, or to take advantage from the positive aspects, when possible. In this sense, this project provides an informative tool aimed to assist policy makers, conservators, architects and other users, in view of an efficient strategy for management and preventive conservation of the European cultural heritage.